Direct-current bus power-loss automatic input device

The utility model belongs to the technical field of power-loss automatic input devices, and particularly relates to a DC bus power-loss automatic input device. Comprising a device shell, a central control device is arranged in the device shell, the central control device is electrically connected with a first voltage transmitter and a second voltage transmitter, a voltage comparator is arranged in the central control device, and a working power supply is further arranged in the device shell. The working power supply is electrically connected with the first voltage transmitter, the second voltage transmitter and the central control device, communicating buses are further arranged in the device shell, a first silicon controlled rectifier and a first diode are arranged in the middle of one communicating bus, and a second silicon controlled rectifier and a second diode are arranged in the middle of the other communicating bus; according to the utility model, the two sets of direct current power supplies can be mu